# 10 CFR § 429.24 - Pool heaters.

§ 429.24 Pool heaters.

(a) Sampling plan for selection of units for testing.

(1) The requirements of § 429.11 are applicable to pool heaters; and

(2) For each basic model of pool heater a sample of sufficient size shall be randomly selected and tested to ensure that any represented value of the thermal efficiency or other measure of energy consumption of a basic model for which consumers would favor higher values shall be less than or equal to the lower of:

$\begin{array}{c}\stackrel{—}{x}=\frac{1}{n}\sum _{i=1}^{n}{x}_{i}\\ \text{and,}\stackrel{—}{x}\phantom{\rule{0ex}{0ex}}\text{is the sample mean; n is the number of samples; and}\phantom{\rule{0ex}{0ex}}{x}_{i}\phantom{\rule{0ex}{0ex}}\text{is the}\phantom{\rule{0ex}{0ex}}{i}^{\mathrm{th}}\phantom{\rule{0ex}{0ex}}\text{sample;}\end{array}$

(i) The mean of the sample, where:

Or,

(ii) The lower 97 1/2 percent confidence limit (LCL) of the true mean divided by 0.95, where:

$\begin{array}{c}LCL=\stackrel{—}{x}-{t}_{.975}\left(\frac{s}{\sqrt{n}}\right)\\ \mathrm{And}\phantom{\rule{0ex}{0ex}}\stackrel{—}{x}\phantom{\rule{0ex}{0ex}}\text{is the sample mean; s is the sample standard deviation; n is the number of}\phantom{\rule{0ex}{0ex}}\\ \text{samples; and}\phantom{\rule{0ex}{0ex}}{t}_{0.975}\phantom{\rule{0ex}{0ex}}\text{is the t statistic for a 97.5% one-tailed confidence interval with n-1}\\ \text{degrees of freedom (from Appendix A).}\end{array}$

(b) Certification reports.

(1) The requirements of § 429.12 are applicable to pool heaters; and

(2) Pursuant to § 429.12(b)(13), a certification report shall include the following public product-specific information: The thermal efficiency in percent (%) and the input capacity in British thermal units per hour (Btu/h).

[76 FR 12451, Mar. 7, 2011; 76 FR 24769, May 2, 2011]